Edgar d



E. DJOHNSON.

I IELEPHONE REPEATER CIRCUITS.

APPLICATION FILED IAN. 4.1918.

Patented Dec. 30, M9

EDGAR D. JOHNSON, OF EAST ORANGE, JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE-REPEATER CIRCUITS.

Specification of Letters Patent.

Patented see. so, one.

Application filed January 4, 1918. Serial No. 210,264.

To all whom it may concern:

Be it known that I, 'EDGAR D. JOHNSON,-

a citizen of the United States, residing at East Orange, in the county of Essex, State of New Jersey, have invented certain new and useful Improvements in Telephone- Repeater Circuits, of which the following is a full, clear, concise, and exact description.

The invention relates to telephone repeater circuits in which a repeater is variably con- .nected between two telephone lines to provicie for the two-Way transmission of signa s.

An object of the invention is to rovide means for automatically connecting t e tele phone repeater properly in response to voice currents impressed on the telephone line, whereby the two-way transmission of signals is made possible.

This is accomplished by means of a single repeating unit, the input side of which is normally connected to both telephone lines. A voice relay is provided for each line, the voice relay associated with the line carrying the incoming signals automatically responding to the voice currents, to disconnect the input side of the repeater from the outgoing line and to connect the output side of the repeater to the outgoing line. The other voice relay effects a similar change in the connections of the repeater for voice currents originating in the other line. In order to makesure that the proper voice relay will be operated, the input side of ,therepeater is given a low impedance. Voice currents coming in over either line are shunted through the low impedance input side of the repeater, thereby operating the proper voice relay which is on the near side of the repeater, but not operating the improper relay on the far side. The operation of either voice relay serves to render the other one ino-p'e ative, so that control of the repeater circuit connections is maintained by one voice relay or the other.

The invention will be more specifically described in connection with the drawing which shows diagrammatically a repeater circuit provided with switching means whereby the two-way transmission of signals is provided. 0 In the drawing the repeater 1 is connected between the two telephone lines 2 and 3. This repeater, while here shown as. of the mechanical type, may be of any other welland the armature 6 of the voice relay '5', the

known type. Between the repeater and the line 2 is electromagnetic switch i, the solenoid of which is normally energized through the circuit including the battery 5 circuit through the armature of vibrating contact 6 of the voice relay 7 being normally closed through its stationary contact 8. The switch 4 is provided with two armatures J and 10 which serve to normally connect the line 2 to the input leads 11 and 12 oi the re peater. The input side of the repeater, in cluding the leads 11, 12 and solenoid 13, has, an impedance which is low as compared to that of either line section, so as to effectively stop the incoming voice currents at the repeater so that the voice relay at the near side of the repeater and not the one at the far side will be operated. In series with the line 2 and located between the armature 9 1 and the lead 11 is the solenoid of the voice relay 1%. The voice relay 1% controls the vibrating contact 15 which, when the reiay is deenergized, is in contact with its stationary switch 16. 3,

The voice relays 7 and Illare similar and when energized set their movable armatures into vibration, thereby interrupting the circuits in which their contacts are included. The invent-ion is not restricted. to any pa ticular type ofvoice relaythat may be employed, and by way of exampie it in cated that these relays may be of the i rm shown in a patent to Brown 1,185,472, to. lephony, May 30, 1916. The contacts l5 and 16 of relay 14 are in series with the electromagnetic switch 17, similar to i, in circuit. with the solenoid of which is a battery 18. The contacts 15a-nd 1Q being nor wlly closed, the switch 17 is normally cnei and its armatures l9 and 20 assume the tions shown in the d 'awing, thereby r necting the line 3 to the incomic l and 1 2 of the repeater. The on 21 and 22 of the repeater contacts 23 and (of the and 26 (of the switch 1'2"). side of the repeater is thus normally d nected from both telephone lines, wh incoming leads are normally sonnet both.

If voice current originates i the voice relay is is energir brating its contacts and swi ch 17, which tit 'connection without interference from the other voice relay 7, the latter having been rendered inoperative by having the circuit through its solenoid opened when the armature 20 moved from its normal position. When those currents are no longer impressed on the line 2, the contacts 15 and 16 assume their normal closed position, thereby en rgizing the switch 17 and again connecting the lHCOIl'illlg side of the repeater to both lines and disconnecting its outgoing side from both lines.

When voice currents originate in the line 3 the voice relay 7 vibrates its contacts to deenergize the switch 4, thereby disconnect-- ing the incoming leads 11 and 12 from the line 2 and connecting the-outgoing leads 21 and 22 of the repeater to the line 2. With the armatures 9 and 10 in their alternate positions and the armatures 19 and 20 in the position shown in the drawing, the repeater is properly connected for repeating signals from the line'3 to the line 2. The armature 9 in moving to its upper contact opens up the circuit through the voice relay 14, thereby rendering the same inoperative, the control being maintained by the voice relay 7 as long as signals are coming in through the line 3.

lVhile only a single embodiment of the invention has been shown, it is obvious that the invention is capable of expression in various other embodiments.

What is claimed is: 1. The combination of two lines, a repeater therebetween, said repeater havingits input side normally connected to both of said lines, a switch comprising a solenoid and an armature controlled thereby between said repeater and each of said lines, and a voice relay between each line and said repeater and adapted to control one of said switches.

2. A signaling system comprising two lines, a repeater therefor, said repeater having its, input side normally connected to both and its output side normally disconnected from both of said lines, and means responsive to voice currents to disconnect the input side of said repeater from one of said lines and to connect said last mentioned line to the output side of said re eater, said ineans comprising relays individ ilal to said mes.

3. Two telephone lines, a repeater therefor, a switch between each line and said repeater, a solenoid for each of said switches, a voice relay in series with each of said lines, a vibratile contact for each of said relays, each of said vibratile contacts being individual to one of said solenoids and with a source of current whereby said solenoids are normally energized. 4. The combination of two telephone lines, a repeater having its input side normally connected to both of said lines, and switching means for disconnecting said input side from one of said lines and for connecting the output side of said repeater for trans mission from one of said lines to the other, saidmeans comprising voice relays having armatures individual tosaid lines.

5. The combination of two lines, a re peater having its input side normally connected to both of said lines, airelay and two armatures controlled thereby between each of said lines and said repeater, each side of said line being connected to one of said armatures, and means responsive to voice currents to switch said repeater, whereby the two-way transmission of current is made possible.

6. The combination of two telephone lines, a repeater therefor, switching means between said repeater and each of said lines, and a voice relay in series with each of said lines and individual to said switching means.

7. The combination of two lines and a repeater therebetween having its input side connected across said lines, said input circuit having an impedance which is low as compared to that of either of said lines, whereby current impressed on said lines is effectively diverted into said input circuit.

8. The combination-of two lines, a repeater therebetweenhaving its input side connected across said lines, said input circuit having an impedance which is low as compared to that of either of said lines whereby current impressed on said lines is effectively diverted into said input circuit, and means responsive to current impressed on said lines for renderin said repeater effective for two-way repeating;

9. The combination of two lines, a re peater therebetwee'n having its input side connected across said lines, said input circuit having an impedance which is low as compared to that of either of said lines whereby current impressed on said lines is effectively diverted into said input circuit, and means responsive to said current impressed on said lines for reversing the connections of said repeater between said lines.

In witness whereof, I hereunto subscribe my name this 29th day of December, A. D.

EDGAR D. JOHNSON. 

